yeah they told us we could do both hands or one... some girls couldnt reach without shoes, so make sure you try at home first... i never tried since im 5'9 already haha, for once in my life i was happy to be tall... but a lot of the tiny girls reached with ease... actually surprised me that some of the 5'2 girls also reached with total ease... :)
just make sure that your finger visibly goes over the line... if its touching the line, they wont accept it unless it visibly corsses it